PWM frequency repeater

RE: PWM frequency repeater

FormerMember — Tue, 20 Mar 2018 08:20:07 GMT

Okay, I see. To debug the problem, I would think the easiest is to use logging over UART/RTT, and for example print the value of "freq" every time it is being updated in ppi_pwm_in_measured_freq().

RE: PWM frequency repeater

ArtG89 — Mon, 19 Mar 2018 14:19:54 GMT

Here how it looks like for second question

RE: PWM frequency repeater

ArtG89 — Mon, 19 Mar 2018 13:47:26 GMT

Yes, it needs external signal from signal generator or other board.

RE: PWM frequency repeater

FormerMember — Mon, 19 Mar 2018 13:38:32 GMT

When I test here, the frequency on PPI_PWM_OUT_PIN never changes because the measured frequency in ppi_pwm_in_measured_freq() always is '0' (the value of PPI_PWM_IN_COUNTER->CC[0] is always '0').

RE: PWM frequency repeater

ArtG89 — Sat, 17 Mar 2018 14:02:23 GMT

In my email, there is message, that You don't see any toggling on pin 6 nor pin 8, even with the prescaler set to '1'. I use my own board with these pins not nrf52-dk (on nrf52-dk these pins used for something else, as I remember uart), on nrf52-dk I'd tried pins 30 and 31. Please inform when You can run my code. One pin is input for measure pwm, and other is output pwm.

RE: PWM frequency repeater

ArtG89 — Fri, 16 Mar 2018 18:55:30 GMT

Thanks for answer.

I need to control the frequency continuously. PWM peripheral based on this topic can change only duty, so I will have to uninitialize and reinitialize the hardware to change the frequency and it will cost some delay. Now I'm not sure will this delay be normal for the final device (more likely no than yes), so I chose PPI.

RE: PWM frequency repeater

FormerMember — Fri, 16 Mar 2018 15:19:49 GMT

I'm testing the code here, but I to come back to the testing on Monday.

Is there a specific reason why you generate the PWM signal using PPI and GPIOTE? If not, I would recommend you to use the PWM peripheral instead, it is a lot easier to use. As a starting point, you can use the pwm_driver example.